Not applicable.
The invention relates to a method and apparatus for producing a synthesis gas from a variety of hydrocarbons. This process can be adjusted to provide synthesis gases that are preferentially concentrated with either hydrogen, carbon monoxide, and/or methane. The apparatus (device) consists of a semi-batch, non-constant volume reactor to generate a synthesis gas. The apparatus feeds mixtures of air, steam, and hydrocarbons into a cylinder where work (i.e. compression) is performed on the fluid by a piston to adiabatically raise its temperature without heat transfer from an external source.
As predicted by the ideal gas laws, or other applicable equations of state, the temperature of the synthesis gas products will decrease as the volume of the cylinder increases, which is required for work extraction. The raw materials (i.e. air, steam, and hydrocarbon fuel) must be compressed to high temperature to facilitate the necessary reforming reactions. This temperature lowering is thought to be advantageous because many applications using synthesis gas requires a lower temperature than is needed to initiate reforming reactions. Furthermore, a high temperature product often leads to energy losses that cannot be recovered. By allowing the high temperature fluid to generate work, the system recovers energy that might otherwise be wasted.
This process is advantageous with respect to current processes because: (1) It can be started and stopped within seconds, (2) Heat Transfer is not required from external sources, (3) Poisons, such as sulfur, nitrogen, and metals, do not adversely affect the process or equipment, (4) Organic sulfur compounds, such as mercaptans, thiophenes, and poly-ring sulfur-bearing aromatics, are thermally decomposed to hydrogen sulfide, which is easily removed with multiple conventional technologies.
The method""s quick start capability shares an advantage with internal combustion engines. However, the method can start and stop much more readily than continuous flow reactor technologies. Being sulfur tolerant, the method also shares this advantage with internal combustion engines. Many catalyst-based systems are poisoned by sulfur (most notably steam reforming systems).
The method""s sulfur conversion capabilities out performs other methods such as, Fluidized Catalytic Cracker (FCC) technology for the conversion of complex sulfur compounds into hydrogen sulfide. While the FCC and other Hydrodesulfurization Technologies do this also, these reactor systems cannot co-produce syngas and perform hydrodesulfurization.
Only the internal combustion engines are as small as the apparatus. However, the internal combustion engines cannot perform the desired reactions for syngas production.
The method and apparatus reduce the need for capital equipment. Since high temperatures are generated from compression and lower temperatures are achieved via expansion (work recovery), there is no need for heat transfer equipment. This aspect reduces cost, size, and operating complexity.
The method allows for co-production of chemical product and mechanical work. The method can be controlled to produce 100% work at desired parts of the duty-cycle. Similarly, the method maximizes syngas production at other parts of the duty cycle.
The invention provides a method and apparatus for producing a synthesis gas from a variety of hydrocarbons. The apparatus (device) consists of a semi-batch, non-constant volume reactor to generate a synthesis gas. The apparatus feeds mixtures of air, steam, and hydrocarbons into a cylinder where work is performed on the fluid by a piston to adiabatically raise its temperature without heat transfer from an external source.
It is an objective of the method to produce synthesis gas without the use of heat transfer.
Another objective of the method is to convert sulfur into hydrogen sulfide.
It is another objective of the method to provide a quick start and stopping procedure for producing synthesis gas.
It is an object of the method to co-produce chemical product and mechanical work.
It is an object of the apparatus to process methane into a synthesis gas.
Finally, it is an object of the apparatus to reduce the size and cost in the production of synthesis gas products.